Machine-Type Communication (MTC) is a form of data communication which involves one or more entities that do not necessarily need human interaction. MTC is an important and growing revenue stream for wireless network operators. MTC devices, such as monitors, sensors, controls, etc., may also be referred to as MTC user equipment (UE). Operators benefit from serving MTC devices with already deployed radio access technology. For example, 3GPP LTE is a competitive radio access technology for efficient support of MTC.
Lower cost MTC devices facilitate and expedite implementation of the concept known as the “internet of things”. In many applications, MTC devices may require low operational power consumption and may communicate with infrequent and short-duration burst transmissions. In addition, MTC devices deployed deep inside buildings may require coverage enhancement in comparison to a defined LTE cell coverage footprint.
3GPP LTE Rel-12 has defined an MTC UE power saving mode that facilitates longer battery life and a new MTC UE category that facilitates reduced modem complexity. Work in Rel-13 is expected to further reduce UE cost and provide coverage enhancement.
For operators to serve MTC devices within a deployed radio access network, such as an LTE network, the MTC devices share the uplink and downlink channels available in the network with traditional UEs such as smartphones, tablets, etc. In an LTE system the available uplink and downlink channels may be described in frequency domain by certain bandwidth and in the time domain by certain subframes. Portions of the available bandwidth and subframes may be allocated for transmission of control information, for user data, or both.
MTC devices may include optimizations to facilitate energy efficient operation and relatively low cost of manufacturing. MTC devices can also co-exist with traditional UEs in the existing framework of an operator's wireless network. To co-exist, MTC devices may share the uplink and downlink resources of the wireless network.
In 3GPP LTE Rel-13 MTC investigation, a key element to enable cost reduction is to introduce reduced UE RF bandwidth of 1.4 MHz, for example, in downlink and uplink within any system bandwidth.
Currently, the LTE specification does not allow a UE to transmit and receive with a reduced RF bandwidth. However Rel-13 MTC UE is only capable of transmitting and receiving with a reduced bandwidth, e.g., 1.4 MHz, in both RF and baseband.